Marks and Spencers has profited from its older customers' spending habits but its chief executive has warned the Government's austerity measures may rain on its parade.

Yesterday's trading update from the department store was its first full update under the leadership of Marc Bolland, who replaced Stuart Rose in the summer.

The better-than-expected figures resulted from more customers coming in and spending more on higher-priced items. "Older customers are better prepared for tougher times. They have seen it before and they have more savings."

But they will not be able to dine out on winter coat purchases forever, he warned, as economic difficulties and rising commodity prices, particularly cotton, all take their toll.

Homewares, clothing and food were bigger draws than ever, with its 'dine in for £10' deal continuing to bring punters into stores. One of its biggest successes has been to consolidate its position as the UK's biggest clothing retailer by growing market share from from 9.6% to 10.3%.

It has had a fruitful autumn in its women's footwear section, selling 300,000 pairs of boots - 50% more than last year. Men's suits and knitwear for men and women also performed well because people were seeking quality rather than quantity.

"With an uncertain environment people are choosing quality. They are choosing things that last, not just for a couple of days or a couple of months," he said.

International sales were up 6% but M&S warned trading was difficult in Ireland and Greece (uncomfortable for the former to be lumped in with the latter.)

One of Mr Bolland's first and biggest tasks as chief executive is a root and branches strategic review of M&S, which will explore issues such as how to attract younger shoppers, whether or not to expand into online grocery deliveries and how to expand internationally.

But while the Government's austerity measures are sure to impact on M&S's figures, Mr Bolland said he was not forecasting a 'double dip'.

Retail consultants have warned that, double dip or not, M&S needs to be prepared for a difficult future, even though its sales have given it gratifying reading.

"The big question mark, and the big challenge for Bolland, is over how long can this performance be sustained," said consultant Neil Saunders.